This invention relates to a bistable tilt liquid crystal memory device and to a method of operating same in order to write, store and read information. More particularly, this invention relates to a liquid crystal memory device utilizing nematic liquid crystals.
Liquid crystal displays are used in various devices, for example, electronic watches and clocks, calculators, instruments such as voltmeters, indicators for temperature, pressure, humidity and speed, etc. Recently, a liquid crystal memory device has been disclosed in the art. This device, which is more fully described in U.S. Pat. No. 3,775,757, utilizes smectic C-phase liquid crystals, the molecules of which are normally tilted with respect to the surface of the display. Upon the application of polarized light in a certain direction, the molecules assume their complementary tilt angles. However, nematic liquid crystals are preferred in most commercial applications, since their properties are better understood and they are more generally available than the smectic C-phase type. Since nematic crystals do not have normal tilt angles and corresponding complementary tilt angles, their use in the device described in the aforementioned U.S. Pat. No. 3,775,757 is precluded.